Which one of the following statements regarding ATDD / BDD is true?

The core principle of both Acceptance Test-Driven Development (ATDD) and Behavior-Driven Development (BDD) is "specification by example." In these approaches, the development team, including business stakeholders, developers, and testers, collaborates to define requirements and acceptance criteria using concrete examples. These examples describe the system's expected behavior from an end-user's perspective, thus serving as test cases that illustrate specific scenarios of product use. This collaborative process ensures a shared understanding of the desired functionality before coding begins.

A. BDD is a collaborative, whole-team activity that occurs before and during development to define requirements, not a siloed test team task performed after requirements are finalized.
C. In ATDD, the test cases are a tangible expression of the acceptance criteria; they are created as the criteria are being defined, not before them.
D. Acceptance tests are first written collaboratively in a business-readable format (e.g., Gherkin). A test automation engineer may later implement them as code, but they do not solely write them. ---

1. ISTQB® Certified Tester Foundation Level Agile Tester Extension Syllabus, Version 1.0, 2014.

Section 3.2.1, Acceptance Test-Driven Development (ATDD), Page 21: "In ATDD, the team discusses requirements and defines acceptance criteria before coding begins. These acceptance criteria are captured as acceptance tests... The acceptance tests are concrete examples of system behavior." This directly supports that tests are examples of product use/behavior.

Section 3.2.2, Behavior-Driven Development (BDD), Page 22: "BDD uses examples to specify behavior... These examples are then formalized into executable specifications." This confirms that BDD also uses examples, which illustrate product use. The section also emphasizes the collaborative nature, refuting options A and D.